JSON_QUOTE(json_val)

Quotes a JSON value: Wraps it with double quote characters and escapes
interior quote and other characters, and returns the result as a
utf8mb4 string. Returns NULL if the argument is NULL.

This function is typically used to produce a valid JSON string literal
for inclusion within a JSON document.

Certain special characters are escaped with backslashes per the escape
sequences shown in
http://dev.mysql.com/doc/refman/5.7/en/json-modification-functions.html
#json-unquote-character-escape-sequences.

URL: http://dev.mysql.com/doc/refman/5.7/en/json-modification-functions.html

